Magic Resistance
Magic resistance is an innate defense mechanism that grants a chance for a spell to completely fail when directed at a creature. The degree of resistance is expressed as a percentage, which reflects its effectiveness against an 11th level spellcaster. When a spell is cast against the creature, a d100 is rolled; if this number is less than the creature's magic resistance, the spell has no effect whatsoever.
However, if a creature's magic resistance fails, in every aspect the spell works as normal. Therefore, the resistant creature would be entitled to a saving throw, if it applied, like any other defender.
Effectiveness
As a general rule, magic resistance becomes 5% less effective against each level of the caster above 11th, and 5% more effective against each level of caster below 11th.
- For example, suppose a creature that has a 25% magic resistance. An 10th level caster suffer a 5% penalty, being one level lower than 11th, increasing the creature's resistance to 30%. Alternately, a 13th level caster would gain 10% on the creature, lowering it's resistance to 15%.
Naturally, the creature could use its magic resistance to overcome magically-conjured barriers, such as those created by firewall, hold portal or forbiddance.
Miscellaneous Notes
Magic resistance also affects the potential for monsters to break through magically-formed barriers, such as hold portal or forbiddance. If met with such a barrier, the creature rolls against its resistance (adjusted by the level of the barrier's caster) — success indicates the barrier is dispelled, not only for the resistant creature but for all others.
Magic resistance does not offer protection from spells that create natural foes, such as monster summoning I or insect plague.
Magic Items, such as scrolls, wands, rods and staves, add +6 to the effective level of the user with respect to magic resistance (but not to the item's power). Thus, a 6th level mage using a wand would be considered 12th level when using that wand against a creature with magic resistance.
Creatures with Magic Resistance
Monsters known to possess magic resistance include:
